Breaker mechanism for a magneto



y 7, 1956 R. E. PHELON BREAKER MECHANISM FOR A MAGNETO Filed April 22, 1953 F/G. 7 Q #1 J9 NM M W T M QQO m P United States Patent BREAKER MECHANISM FOR A MAGNETO Russell E. Phelon, East Longmeadow, Mass.

Application April 22, 1953, Serial No. 350,458

10 Claims. (Cl. Mi -39) This invention relates to improvements in switch construction and, more specifically, to an improved switch or breaker mechanism for a magneto or the like.

While the switch or breaker mechanism of the present invention may find application in many electrical devices, it can be used to particular advantage in a magneto. A breaker mechanism constructed in accordance with this invention may be used in a magneto of the type shown in the Phelon Patent No. 2,472,313.

The general object of the present invention is to pro vide a magneto breaker mechanism which is simple and inexpensive in construction and is reliable in operation.

More specific objects of the invention will be apparent from the drawing and from the following specification and claims.

In the drawing I have shown in detail a preferred embodiment of the invention as particularly adapted to magneto constructions, but it will be understood that various changes may be made from the construction shown and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims forming a part of the specification being relied upon for that purpose.

Of the drawing:

Fig. 1 is an elevational view of the switch or breaker mechanism,

Fig. 2 is a bottom view of the breaker mechanism shown in Fig. 1,

Fig. 3 is a right side view of the breaker mechanism,

Fig. 4 is a cross sectional view in the plane of line 44 of Fig. 1 showing the first step in assembly of the breaker mechanism,

Fig. 5 is similar to Fig. 4 but shows the second stage of assembly,

Fig. 6 shows the third stage of assembly, and

Fig. 7 shows the final assembly of the breaker mechanism.

In the drawing, a preferred embodiment of the switch or breaker mechanism is shown, said embodiment being particularly adapted for installation in a magneto of the type disclosed in the aforementioned Phelon patent. Only so much of the magneto as is necessary to an understanding of the present invention has been shown in the drawing and reference may be had to said patent for a comprehensive description of the other elements of the magneto.

However, to clearly comprehend all of the advantages of the present breaker mechanism, it should be borne in mind that magnetoes are used to generate voltage for the spark plugs of internal combustion engines. It is conventional practice to include in the magneto a rotatable shaft such as the shaft 10 which may be an extension of the engine crankshaft, and in any event the shaft 10 is driven in timed relationship with the engine. It is also customary to arrange a core and field structure (not shown) to establish magnetic circuits through the core during rotation of the shaft. During such rotation, voltage will be generated in the said circuits, the voltage ice reaching maximum values in specific rotated positions of the shaft. It is also conventional practice to provide switch contacts or breaker points, such as the points 12 and 14 shown in the drawing, with means adapted to separate the points at the instant of peak voltage generation or when the shaft reaches said specific rotated positions.

The means adapted to separate the breaker points may include a generally circular cam 16 embracing the shaft 10 and fixed for rotation therewith as by a key 18. it is customary to provide a pivotally mounted contact carrying member in engagement with the periphery of the generally circular cam. One peripheral portion of the cam, such as the portion 20, may be relatively fiat to permit shifting of the pivoted contact carrying member in one direction while the said portion 20 is in engagement therewith. The remaining peripheral portion 22 of the cam 16 will, of course, shift the contact carrying member in the opposite direction while in engagement therewith. Obviously, the breaker points can be selectively arranged to separate during movement of the cam following contact carrying member in either direction. From the foregoing general description, it will be understood that the rotating shaft 10 and cam 16 comprise driven actuating means for the switch breaker mechanism.

In accordance with the present invention the breaker mechanism comprises two major elements, namely, a bracket or support member 24 and a cam following contact carrying member 26.

As will be readily apparent from the drawing, the support member can be conveniently fabricated from flat, preferably metallic, sheet material as by stamping or the like and then formed into bracket shape as shown. When stamped, the member 24 is provided with a straight upper edge 25 and a straight lower edge 27 of reduced width. The longitudinal or side edges are irregularly formed with a laterally extending appendage 28 along the lefthand edge and an oppositely extending appendage 30 along the right-hand edge. A substantially rectangular slot 32 extending longitudinally of the member 24 is provided adjacent the upper edge 25 but in spaced relationship thereto. A substantially longer rectangular slot 34, equal in width and in longitudinal alignment with the slot 32, is provided to extend from the lower edge 27 of the support member 24. A cross piece or bar 36 of substantially square cross-sectional configuration extends across the lowermost slot 34 in spaced relationship to the bottom edge 27.

In forming the support member 24 into bracket shape, the upper and lower portions thereof are bent forwardly at substantially right angles to the body portion 29 so that the upper and lower slots 32 and 34 will be disposed in horizontal planes substantially parallel to the shaft 10 while the body portion extends in a vertical plane substantially perpendicular to the shaft. it is it portant to note that the arrangement of the slots 32 and 34 is such as to assure registry therebetween and align ment with the cam 16 in a common plane with the axis of the shaft 10 when the end portions are bent forwardly and it is also important to arrange the cross piece 36 so that it will be disposed substantially under the center of the upper slot 32.

The appendage 30 along the right-hand edge of the member 24 is formed with a generally rectangular body portion 38 which is spaced from but connected to said edge by an interconnecting section 40 of reduced width. With this form, the appendage 30 can be bent forwardly along the interconnecting section 40 at substantially a right angle to the body of the member 24 as shown. Then the upper part of the appendage body portion 33 is bent inwardly at substantially a right angle to the remainder thereof. Said inwardly bent part of the appendsmooths contact member or point 12, as by no contact face of the point 12 extends owe. and disposed in a horizontal plane.

The appendage 23 along the left-hand edge of the member is provided with an open ended U-shaped slot 1-2 adapted to loosely receive a bolt 44 when the said appendage is bent forwardly at substantially a right angle to the body portion 29 of the support member. The bolt is engaged within a nut 46 and clamps one end of a generally U-shaped spring 48. As will be shown more fully hereinafter, the spring 48 serves as an electrical conductor, so for insulating purposes, a nonconducting sleeve 45 embraces the bolt 44 within the slot 42 and nonconducting washers 47 and 49 are located between the appendage 2% and the nut 46 and spring 4%, respectively. Advantageously, the bolt 44 and the nut 4-6 may also be formed of insulating material.

Also during the initial steps in fabrication of the support member 24, a suitable hole is provided through the body portion 2? thereof to receive a mounting screw 52 which can be threaded into the base or frame 54 included in the magneto structure. The screw receiving openings in the member 24 in the frame 54 are arranged so that the member 24 can be fixedly secured to the frame with the slots 31} and 34 vertically aligned in a diametrical plane through the shaft ill and cam 16.

Preferably, the magneto frame is suitably grounded to effect a ground connection from the point 12 through the bracket 24 and the said frame.

As best shown in Figs. 3 to 7, the cam following contact carrying member 26 is substantially rectangular in cross section as well as in elevation. Preferably, the member 26 is formed of nonconducting material such as pressed fiber and in any event it can be simply and economically fabricated. The thickness and width of the member 26 are determined by the width and length, respectively, of the upper slot 32 in the support bracket 24, the member 26 being dimensioned for a relatively close sliding fit within the said slot. The length of the member 26 is determined by the spacing between slots 32 and 3 5 in the support bracket, the member 26 being sufficiently long to extend well beyond the upper slot 32 and a shorter distance below the lower slot 34. As will be shown in detail hereinafter, the member 26 is adapted to engage the periphery of the cam 16 and slide upwardly and downwardly within the slots 32 and as during rotation of the cam. Accordingly, the member 26. willl hereinafter he called the slide for convenient reference.

The bottom end portion of the slide 26 has a centrally located longitudinally extending keyhole slot 56 comprising a generally elliptical opening 57 and a relatively narrow rectilinear communicating opening 58 which extends to the bottom edge of the slide. The aforementioned keyhole slot 56 is provided to receive the cross piece 36 with the bottom end of the slide disposed in the lower slot 34 of the support bracket. The cross piece 36 is received within the narrow portion 58 of the keyhole slot when the slide is being assembled on the bracket 24 and when the slide is vertically disposed for cam actuated movement. The cross piece 36 is received within the larger generally elliptical opening 57 of the keyhole slot during assembly of the slide to permit pivoting movement of the slide therearound.

A hole of) is provided between the ends of the slide 26 to receive a rivet 62 or similar fastening device which secures an inturned leg 63 on one end of the spring 48 to one face of the slide. The rivet 62 also fastens one leg 6d of an L-shaped contact support 66 to the face of the slide opposite the spring. The other leg 68 of the L-shaped support 66 extends at substantially a right angle to the slide and fixedly secures the breaker point 14 as by a rivet 69.

The slide 26 is assembled relative to the support member of the bracket 24 with the spring 48 and the L-shaped contact support 66 secured thereto as described. The

manner in which the slide 26 is assembled is best shown in Figs. 4 to 7. In Fig. 4, the initial step in assembly is shown wherein the slide-is thrust at substantially a right angle toward the body 29 of the bracket with the cross piece 36 disposed within the narrow portion 53 of the keyhole slot. When the cross piece 36 is received within the elliptical enlarged portion 57 of the keyhole 1 slot as shown in Fig. 5, the slide can be pivoted upwardly around the cross piece to the position shown in Fig. 6. When the slide is vertically disposed, it can then be elevated through the upper slot 32 to the position shown in Fig. 7. in the last-mentioned position, the free end of the spring 48 is clamped by the bolt 4 and nut 46 as shown in Fig. 1. Also, in the position of Fig. 7, the contact surface of the breaker point 14 be will substantially horizontally disposed and vertically aligned for engagement with and disengagement from the breaker point 12 during reciprocation of the slide in a substantially vertical plane.

As previously mentioned, the slots 32 and 34 in the bracket are aligned with the cam 16 and with the axis of the shaft 19. The spring 48 urges the slide upwardly into engagement with the periphery of the cam so that said slide will be reciprocated upwardly and downwardly during rotation of the shaft and the cam. When the peripheral portion 2% of the cam 16 engages the top of the slide 26, the slide will be elevated under the force of the spring 48 to effect engagement between the breaker points 12 and 14, as shown in Fig. 1. When the portion 22 of the cam periphery engages the top of the slide 26 (during peak voltage generation in the magneto), the slide 26 will be thrust downwardly against the force of the spring 48 to separate or disengage the breaker points 12 and 14. At this point it should be noted that the bracket 24 is located sufiiciently close to the periphery of the cam to prevent the slide as from becoming inadvertently disengaged from the lowermost bracket slot when the slide is elevated to its uppermost cam-engaging position. It will be understood that, during rotation of the shaft 10 and cam 16, the slide 26 will be reciprocated upwardly and downwardly toward and from the shaft and cam axis. Such movement of the slide is, of course, rectilinear, the slide being guided within the slots 32 and 34. The front and rear faces of the slot 32 provide bearing surfaces for the slide in engagement with the edges thereof and the front and rear faces of the cross piece 36 provide bearing surfaces for the slide in engagement with the edges of the narrow rectilinear opening 58 in the keyhole slot.

As mentioned hereinabove, the spring 48 serves as an electrical conductor. Accordingly, the bolt 44 constitutes a terminal post (to which the primary coil may be con nected) and an electrical connection is effected through the spring 48, the rivet 62 and contact support 66 to the breaker point 14. However, it will be understood that other or alternative conductor means can be utilized to effect an electrical connection to the breaker point 14.

It will be quite apparent that an important advantage of the invention resides in the arrangement of the slide and the bracket permitting convenient assembly of the slide with the spring and contact carried thereby. Disassembly can also be expeditiously effected for the purpose of repairing or replacing the contact points by merely loosening the spring retaining bolt and removing the spring 48 and the breaker point 14 with the said slide.

1 claim as my invention:

1. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart registering openings disposed in alignment with the cam, a cross piece extending across one of said openings, a slide having a longitudinally extending slot at one end thereof receiving said cross piece within said one opening and having the other end extending through the other opening, means biasing said slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to said slide for reciprocation therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

2. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart registering openings disposed in alignment with the cam, a cross piece extending across one of said openings, a slide having a longitudinally extending slot at one end thereof adapted to receive said cross piece for sliding and pivoting movement therearound whereby said slide can be extended into said one opening with the slot receiving the cross piece and then pivoted into alignment with and extended through the other opening for guided rectilinear movement therethrough, means biasing said slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to said slide for reciprocation therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

3. in a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart openings disposed in alignment beneath the cam, the lowermost of the said openings having one open side, a cross piece extending across said lowermost opening, an elongated slide having a longitudinally extending slot at one end thereof adapted to receive said cross piece for sliding and pivoting movements therearound whereby said slide can be extended into said open side of said lowermost opening with said slot receiving the cross piece and then pivoted upwardly into alignment with and extended through the uppermost opening for guided rectilinear movement therethrough, means biasing said slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to the slide for reciprocation therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

4. in a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart openings disposed in alignment beneath the cam and in a plane with the axis of the shaft, the lowermost of said openings having one open side, a cross piece of substantially square cross section extending across said lowermost opening, an elongated slide having a longitudinally extending keyhole slot at one end thereof, the reduced width portion of said slot being adapted to receive said cross piece in close sliding relationship and the enlarged portion of said slot being adapted to loosely receive said cross piece for pivoting movement of said slide therearound whereby said slide can be extended into said open side of the lowermost opening with said cross piece received in said reduced portion of the slot and then in the enlarged portion thereof to permit pivotal movement of said slide into alignment with the uppermost opening for extension and guided rectilinear movement therethrough, means biasing said slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to said slide for reciprocation therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

5. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart registering slots disposed in substantially vertical alignment beneath the cam and in a plane with the axis of the shaft, the lowermost of said slots having one open side, a cross piece of substantially square cross section extending across said lowermost slot, an elongated substantially rectangular slide having a longitudinally extending keyhole opening in one end thereof, the reduced width portion of said opening being adapted to receive said cross piece in close sliding relationship and the enlarged portion of said opening being adapted to loosely receive the cross piece for pivoting movement of the slide therearound whereby said slide can be extended into said open side of the lowermost slot with said cross piece received in said reduced portion of the opening and then in the enlarged portion thereof to permit pivotal movement of the said slide into vertical position and extension and guided rectilinear movement through the uppermost slot, means biasing said slide upwardly into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to said slide for reciprocation therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

6. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of support means having a pair of spaced apart registering slots disposed in substantially vertical alignment beneath the cam and in a plane with the axis of the shaft, the lowermost of said slots having one open side, a cross piece of substantially square cross section extending across said lowermost slot, an elongated substantially rectangular slide having a longitudinally extending keyhole opening in one end thereof, the reduced width portion of said opening being adapted to receive said cross piece in close sliding relationship and the enlarged portion of said opening being adapted to loosely receive the cross piece for pivoting movement of the slide therearound whereby said slide can be extended into said open side of the lowermost slot with said cross piece received in said reduced portion of the opening and then in the enlarged portion thereof to permit pivotal moveent of said slide into substantially vertical position and extension and guided movement through the uppermost slot, spring means secured to one side of said slide biasing the slide upwardly into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact fixed to another side of said slide for reciprocation thereof, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation thereof.

7. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of a support bracket having a body portion disposed at substantially a right angle to the shaft and having upper and lower forwardly extending portions defining openings in alignment with the cam and in a plane with the axis of the shaft, a slide extending through said openings, a first forwardly extending appendage on said bracket, an electrical conducting spring member disposed between said appendage and said slide to bias the slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, electrical insulating means separating said spring and said first appendage, a first contact electrically connected to said spring and carried by said slide, a second forwardly extending appendage on said bracket, and a second contact secured to said second appendage for engagement by said first contact during each reciprocation of said slide.

8. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of a support bracket disposed at substantially a right angle to the shaft and having a pair of forwardly extending portions substantially parallel to the shaft and defining a pair of spaced apart slots in alignment beneath the cam and in a plane with the axis of the shaft, the lowermost of said slots having one open side, a cross piece extending across said lowermost slot, an elongated generally rectangular slide having a longitudinally extending opening at one end thereof adapted to receive said cross piece for sliding and pivoting movements therearound w iereby said slide can be extended into said open side of said lowermost slot with said opening receiving said cross piece and then pivoted upwardly into alignment with and extended through the uppermost slot for guided rectilinear movement, a first forwardly extending appendage on said bracket, a spring disposed between said first appendage and said slide to bias the slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact secured to said slide for reciprocation therewith, a second forwardly extending appendage on said bracket, and a second contact fixed to said second appendage for engagement by said first contact during each reciprocation thereof.

9. in a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of a support bracket disposed at substantially a right angle to the shaft and having a pair of forwardly extending portions substantially parallel to the shaft and defining a pair of spaced apart slots in aligninent beneath the cam. and in a plane with the axis of the shaft, the lowermost of said stots having one open side, a cross piece of substantially square cross section extending across said lowermost slot, an elongated substantially rectangular slide having a longitudinally extending keyhole opening at one end thereof, the reduced width portion of said opening being adapted to receive said cross piece in close Sliding relationship and the enlarged portion of said opening being adapted to loosely receive the cross piece for pivoting movement of said slide whereby said slide can be extended into the open side of said lowermost slot with said cross piece received in said reduced portion and then in said enlarged portion of said opening to permit pivotal movement of the slide into alignment with the uppermost slot and extension therethrough for guided rectilinear movement, a first forwardly extending appendage on said bracket, a spring disposed between said first appendage and said slide to bias the slide into engagement with the cam to enable the said cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact secured to said slide for reciprocation therewith, a second forwardly extending appendage on said bracket, and a second electrical contact fixed to said second appendage for engagement by said first contact during each reciprocation thereof.

lO. In a breaker mechanism for a magneto or the like which includes a rotatable shaft and a cam fixed thereto, the combination of a support bracket having a body por tion disposed at substantially a right angle to the shaft and having two spaced apart portions extending forwardly of said body portion and defining openings in alignment with the cam and lying substantially in a plane which includes the axis of the shaft, a slide extending through said openings, a first forwardly extending appendage on said bracket, an. electrical conducting spring supported by said first appendage and connected to said slide between said openings to bias the slide into engagement with the cam so as to enable the cam to reciprocate the slide toward and away from the axis of the shaft, a first electrical contact electrically connected to said spring and carried by said slide between the said openings, at second forwardly extending appendage on said bracket, and a second electrical contact secured to said appendage for engagement by said first contact during each reciprocation of said slide.

References Cited in the file of this patent UNITED STATES PATENTS 2,010,957 Mack Aug. 13, 1935 2,106,721 Chermendy Feb, 1, 1938 2,129,953 Mack Sept. 13, 1938 2,384,828 Fuston Sept. 18, 1945 2,464,779 Brownlee et al. Mar. 15, 1949 

